class Node {
    public int data;
    public Node next;

    public Node(int data) {
        this.data = data;
    }
}
public class MyQueueLinked {

    private Node front;
    private Node rear;
    private int usedSize;

    /**
     * 入队列
     * @param val 值
     */
    public void offer(int val) {
        Node data=new Node(val);
        this.usedSize++;
        if(this.front==null){
            this.front=data;
            this.rear=data;
            return ;
        }
        data.next=this.front;
        this.front=data;
    }

    /**
     * 出队头元素
     * @return
     */
    public int poll() {
        return -1;
    }

    /**
     * 得到队头元素 但是不删除
     */
    public void peek() {

    }

    public boolean isEmpty() {
        return false;
    }

    public int size() {
        return -1;
    }


}